A review of carcass conformation in sheep: assessment, genetic control and development

Stud breeders, farmers and meat traders have considered carcass conformation or shape in sheep an important trait. This trait can be assessed on either carcasses or live animals for slaughter and breeding. Nevertheless, there is no single universally accepted de®nition of the term carcass conformation across the sheep industry. The use of the word carcass conformation in the sheep industry is further confused by the fact that different indices are used to describe a complex 3-dimensional shape, which causes variation in the interpretation of results. This review of current knowledge on carcass conformation in sheep will identify areas, which offer opportunities for research. Visual carcass conformation appears to be poorly related to meat yield and is also probably predominantly under non-genetic control and as such has little commercial relevance. Visual carcass conformation assessments appeal to farmers because they are cheap and easy to apply. In contrast, objective conformation and muscularity (another measure of conformation) require measurements, which may be complicated, dif®cult or costly depending on the system under consideration. However, precisely de®ned objective conformation and muscularity, which can be standardised and automated are desirable in breeding and carcass classi®cation schemes. Though, muscularity is highly heritable and is positively related to meat yield, information on objective conformation, muscularity and, their relationships to meat yield and other production traits is not adequate. Furthermore, there is little information on whether objective conformation is under genetic or non-genetic control. Provision of such information would lead to the design of ef®cient sheep production systems. # 2000 Elsevier Science B.V. All rights reserved.